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+To use SNTP support, add a define CFG_CMD_SNTP to CONFIG_COMMANDS in
+the configuration file of the board.
+
+The "sntp" command gets network time from NTP time server and
+syncronize RTC of the board. This command needs the command line
+parameter of server's IP address or environment variable
+"ntpserverip". The network time is sent as UTC. So if you want to
+set local time to RTC, set the offset in second from UTC to the
+enviroment variable "time offset".
+
+If the DHCP server provides time server's IP or time offset, you
+don't need to set the above environment variables yourself.
+
+Current limitations of SNTP support:
+1. The roundtrip time is ignored.
+2. Only the 1st NTP server IP, in the option ntp-servers of DHCP, will
+ be used.